nelson mandela transformed his nation and the world. a freedom fighter with the grace and courage to forgive his oppressors. inspiring generations of civil rights leaders at a young barack obama who recalled a rally on his own college campus. >> my very first political action, first thing i ever did that involved an issue or a policy or politics was a protest against apartheid. >> reporter: as a senator obama had visited mandela, and the president and mrs. obama brought their doubters to robben island prison so they could better understand what mandela had suffered. after he died, michelle obama tweeted we will forever draw strength and inspiration from nelson mandela's extraordinary example of moral courage, kindness and humility. bill clinton tweeted a picture and wrote, "i will never forget my friend madibaa," use the affectionate name by which mandela was known to his followers. mandela wasn't always on the u.s. side. in the 1980s president reagan supported apartheid regime, and eastern as protests broke out an college campuses acro